Electric Current (Electromagnetism)
Drift of electric charges, current density, resistance, conductivity, and Joule heating.
General idea of the topic
Electric current connects moving charge with the quantities that define a circuit: voltage, resistance and power. The goal is to model direct-current networks and simple transient responses.
The block progresses from the definition of current intensity and Ohm's law to Kirchhoff's laws and RC circuits, providing the tools to analyze any DC network with full physical coherence.
What you will truly understand
- How to define and measure current intensity.
- How to use Ohm's law with its domain of validity.
- How to size power and avoid thermal overload.
- How to solve series/parallel networks and meshes with Kirchhoff.
- How to interpret RC transients in time.
Recommended learning route
- Current intensity.
- Resistance and Ohm's law.
- Electrical power.
- Direct-current circuits.
- RC circuits.
Physical criterion you must acquire
Do not solve by recipe: first decide the model (linear, nodal, transient), then apply equations and validate units, signs and power.
Connection with real problems
Appears in wiring, protections, electronics, timing, filters and fault diagnosis in electrical networks.
Final goal of the topic
Solve and justify electric current circuits with full physical traceability and verifiable results.
Topics in this section
- Electric Current (Electric Current)
Electric charge flow per unit time and its interpretation in circuits and conductive materials.
- Resistance and Ohm's Law
Macroscopic and microscopic relationships between voltage, electric current, resistance, and resistivity.
- Electric Power
Rate of electric energy transfer and design criteria for thermal behavior, efficiency, and circuit safety.
- Direct-Current Circuits
Kirchhoff's junction and loop rules for systematic direct-current network analysis.
- RC Circuits
Time evolution of voltage and current in first-order resistor-capacitor networks under transient regime.